Manufacture of underground-telegraph lines



(No Model.)

W. R'. PATTERSON. Manufacture of Underground Tlegraph Lines.

Patented March 29,1881

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"Witnesses ETERS PHDTOLITHOGRAPHER. WASMNGTOH, D. C,

UNITED STATES PATENT OFFICES WILLIAM R. PATTERSON, OF EVANSTON, ASSIGNOR TO IVESTERN ELECTRIC MANUFACTURING COMPANY, OF CHICAGO, ILLINOIS.

MANUFACTURE OF UNDERGROUND-TELEGRAPH LINES.

SPECIFICATION forming part of Letters Patent N0. 239,539, dated March 29, 1881.

Application filed December 13, 1880. (No model.)

To all whom it may concern: and where there will be comparatively much 7 Be it known that I, WILLIAM R. PAITER- more escape than elsewhere, owing perhaps to soN, of Evanston, in the county of Cook and an impurity in the fiber, to the presence of a State of Illinois, have invented a new and usedrop of water, or to the distance between the 55 ful Improvementin the Manufacture of Underwires being reduced by twisting or bending. ground-Telegraph Lines, of which the follow- The current thus escaping from a conductor ing is a specification. to the ground or neighboring conductors will My invention relates to the preparation of decompose the film ofsulphide of copper. This the copper conductingwires and the fibrous is most noticeable where theinsulation is poor- 60 1o material with which they are covered; and it est. The sulphur will immediately take hyconsists in removing therefrom all substances drogen from theoil, forming hydrogen sulphide. which would be detrimental to the mainte- The tendencyis to deposit the metallic copper nance of the integrity and insulation of the produced bythedecompositionat theuegative conductors of oil-cables. electrode, but it is retained by the fibers of 65 I have found that there are on the surface the covering. The hydrogen sulphide, held of copper wire of commerce many kinds of subfrom escaping in bubbles by the same cause, stances the presence of which in a cable of is left to combine again with the copper of this character has always proved injurious. the wire, forming again sulphide of copper. Among the injurious substances 1 have found This will again be decomposed by the action 70 2o sulphide of copper, chloride of copper, sodium, of the current, and more copper will be deposand other metals, and oxide of copper, iron, ited iu the fiber. By a continuation of this and other metals. Oxide of copper is always action copper will be gradually deposited in present, being formed by the process of anthe fiber, until ultimatelythe time dependnealing, and by the necessary or accidental eX- ing on the original degree of insulation, the 75 posnre in transshipment or storage to air conamount-of available sulphide, and the strength taining oxidizing agents. The sulphide is also of the current-a fault will be developed which sometimes present, being formed by similar will interrupt the working of the line. lfsulexposure. The sulphate may be formed by the phate of copper is present in a cable of this action of a minute quantity of sulphuric acid kind, it will in like manner be decomposed by So in the oil, aided by the heat necessary to on the current escaping, and the metallic copper pel the moisture at one stage of the manufacwill be deposited upon the fibrous covering. ture, or by other accidental means. Chloride The oil and oxide present furnish the eleof copper may be formed resulting from the inents necessary to unite with the other propresence of chlorine in some combination, reducts resulting from the decomposition of the 8 5 mainin g after the bleaching process to which sulphate of copper, and form sulphuric acid, the cotton must be subjected. Salts of other which, if in sufficient quantity, will attack the metals, when found, are usually in the fibrous wire, and the process of decomposition and covering, and iron oxide may be present in fine combination will be repeated until the insulapa-rticles coming from the iron pipe generally tion is destroyed. When chloride of copper 9o 40 used. The oxides and other unavoidable coinis present it will in a similar manner be depounds are generally uniformly distributed, composed, and result in the deposition of mewhile the accidental compoundssuch,for eX- tallic copper upon the fibrous covering and ample, as may be formed from a drop of acid the formation of hydrochloric acid, which at only occur here and there. Any given piece tacks the wire and forms a chloride which is 5 of commercial copper wire, such as is used for again decomposed. In a like manner any meother telegraphic purposes and such as heretallic salt decomposed by a current of electofore has been used in cables, is liable to be tricity seems to result in the formation of the tarnished by one or more of the substances corresponding acidby aid of hydrogen fromthe mentioned. Although the wires all test well oil. IV hen an oxide of copper or other metal 100 at first, there will in all probability be some is subjected to the action of the current in point where the insulation will be imperfect, presence of oil, the insulation of the wires rapidly deteriorates, and the oil is found to contain traces of water.

When any of the substances I have mentioned as being injurious when 011 the surface of the copper wire are present in the fiber with which the wire is wound, chemical reactions similar to those I have described above are liable to occur to the injury of the cable. Unbleached cotton yarn--the only material that has been heretofore used to insulate the wires in this class of cables---[ find always contains, in addition to other impurities, lumps of natural gums, which lower the insulation where they occur, and thereby occasion greater escape at certain points, resulting in more energetic chemical action when certain other impurities are present either in the cotton or oil or upon the wire. I have known cables in actual use to gradually deteriorate and fail from several of the causes I have mentioned, and have demonstrated by chemical experiment and analysis the possibility of such failure from any of them.

I prevent the destruction of the cable from any of the causes which I have mentioned in the following manner: By means of stiff wire scratch-brushes revolving against the wire, or by a dipping process of potash, dilute acid, and water-baths, I thoroughly remove all foreign substances from the surface of the copperwire. Then,immediately after the wire has been thus thoroughly cleaned, and in order to prevent a new coating ofinjnrious substances from forming on the wire, I cover it with a coating of shellac, lacquer, paraifine, or other suitable material.

In the drawings, Figure 1 represents a piece of copper wire of commerce with its coating, I), of impurities.

a, Fig. 2, shows the wire with the impurities removed.

0, Figs. 3 and 4, shows the coating of shellac or other chemically inert substance.

Fig. 5 is a transverse section of an oil-cable containing wires, a, thoroughly cleaned and formed into a cable of insulated conductors. The Wires are covered with fibrous coverings g and bound together by covering f, said coverings ot'fibrous material being thoroughly washed, as before described.

The iron pipe d and oil 0 are used in the ordinary way.

In place of unbleached cotton yarn I use that which is bleached and thoroughly washed, so as to remove all traces ofan y chloride which may be present from bleaching processes.

After the copper wire and fibrous covering are thus prepared 1 wind the wires and 0011- struct and lay the cable in the usual manner.

Prior to my invention it was customary to use shellac applied directly to theimpure surface of copper wire of commerce. The yarn was wound upon this coating of shellac and embedded therein by heating the wire thus covered. The shellac thus used served to improve the insulation of the wire and prevent the cotton from unwinding or slipping; but all the original impurities were left upon the wire.

I use shellac or other chemically inert substance upon the clean surface of copper wire to keep it clean during the subsequent steps of the process of its manufacture and until it is all ready to be drawn within the pipe.

Gables are always heated or baked to expel all moisture before they are drawn within the iron pipe. This necessary heat effectually dissipates the very thin coating of shellac that I use to keep the surface of the wire clean during the process of its manufacture. The shellac has thus done its work when the cable is ready to go into the drying-oven.

I have pointed out one way of cleaning the wire. There are other ways of cleaning wire well known to those skilled in the art.

I claim The process consistingof cleaning the wire, applying a coating of shellac to keepit clean, covering the wire with clean fibrous material, and then forming the wire thus insulated into a cable and drying the cable, whereby the shellac is dissipated, substantially as described.

WILLIAM 1-2. PATTERSON.

Witnesses:

'lrrno. HARBIG, STEPHEN D. FIELD. 

